Recently, power generation systems using natural energy attract attention, and photovoltaic power systems have been actively introduced. Photovoltaic generation uses a solar battery (PV: Photovoltaic) for converting energy of sunlight into electric power. However, a solar battery panel does not satisfy an operable voltage of an inverter.
Incidentally, there are needs for an increase of the amount of power generation and a further reduction of manufacturing cost of a photovoltaic power system.